/*
 * jQuery UI Nested Sortable
 * v 1.3.5 / 21 jun 2012
 * http://mjsarfatti.com/code/nestedSortable
 *
 * Depends on:
 *	 jquery.ui.sortable.js 1.8+
 *
 * Copyright (c) 2010-2012 Manuele J Sarfatti
 * Licensed under the MIT License
 * http://www.opensource.org/licenses/mit-license.php
 */

(function($) {

    $.widget("mjs.nestedSortable", $.extend({}, $.ui.sortable.prototype, {
        options: {
            tabSize: 20,
            disableNesting: 'mjs-nestedSortable-no-nesting',
            errorClass: 'mjs-nestedSortable-error',
            doNotClear: false,
            listType: 'ol',
            maxLevels: 0,
            protectRoot: false,
            rootID: null,
            rtl: false,
            isAllowed: function(item, parent) {
                return true;
            }
        },
        _create: function() {
            this.element.data('sortable', this.element.data('nestedSortable'));

            if (!this.element.is(this.options.listType))
                throw new Error('nestedSortable: Please check the listType option is set to your actual list type');

            return $.ui.sortable.prototype._create.apply(this, arguments);
        },
        destroy: function() {
            this.element
                    .removeData("nestedSortable")
                    .unbind(".nestedSortable");
            return $.ui.sortable.prototype.destroy.apply(this, arguments);
        },
        _mouseDrag: function(event) {

            //Compute the helpers position
            this.position = this._generatePosition(event);
            this.positionAbs = this._convertPositionTo("absolute");

            if (!this.lastPositionAbs) {
                this.lastPositionAbs = this.positionAbs;
            }

            var o = this.options;

            //Do scrolling
            if (this.options.scroll) {
                var scrolled = false;
                if (this.scrollParent[0] != document && this.scrollParent[0].tagName != 'HTML') {

                    if ((this.overflowOffset.top + this.scrollParent[0].offsetHeight) - event.pageY < o.scrollSensitivity)
                        this.scrollParent[0].scrollTop = scrolled = this.scrollParent[0].scrollTop + o.scrollSpeed;
                    else if (event.pageY - this.overflowOffset.top < o.scrollSensitivity)
                        this.scrollParent[0].scrollTop = scrolled = this.scrollParent[0].scrollTop - o.scrollSpeed;

                    if ((this.overflowOffset.left + this.scrollParent[0].offsetWidth) - event.pageX < o.scrollSensitivity)
                        this.scrollParent[0].scrollLeft = scrolled = this.scrollParent[0].scrollLeft + o.scrollSpeed;
                    else if (event.pageX - this.overflowOffset.left < o.scrollSensitivity)
                        this.scrollParent[0].scrollLeft = scrolled = this.scrollParent[0].scrollLeft - o.scrollSpeed;

                } else {

                    if (event.pageY - $(document).scrollTop() < o.scrollSensitivity)
                        scrolled = $(document).scrollTop($(document).scrollTop() - o.scrollSpeed);
                    else if ($(window).height() - (event.pageY - $(document).scrollTop()) < o.scrollSensitivity)
                        scrolled = $(document).scrollTop($(document).scrollTop() + o.scrollSpeed);

                    if (event.pageX - $(document).scrollLeft() < o.scrollSensitivity)
                        scrolled = $(document).scrollLeft($(document).scrollLeft() - o.scrollSpeed);
                    else if ($(window).width() - (event.pageX - $(document).scrollLeft()) < o.scrollSensitivity)
                        scrolled = $(document).scrollLeft($(document).scrollLeft() + o.scrollSpeed);

                }

                if (scrolled !== false && $.ui.ddmanager && !o.dropBehaviour)
                    $.ui.ddmanager.prepareOffsets(this, event);
            }

            //Regenerate the absolute position used for position checks
            this.positionAbs = this._convertPositionTo("absolute");

            // Find the top offset before rearrangement,
            var previousTopOffset = this.placeholder.offset().top;

            //Set the helper position
            if (!this.options.axis || this.options.axis != "y")
                this.helper[0].style.left = this.position.left + 'px';
            if (!this.options.axis || this.options.axis != "x")
                this.helper[0].style.top = this.position.top + 'px';

            //Rearrange
            for (var i = this.items.length - 1; i >= 0; i--) {

                //Cache variables and intersection, continue if no intersection
                var item = this.items[i], itemElement = item.item[0], intersection = this._intersectsWithPointer(item);
                if (!intersection)
                    continue;

                if (itemElement != this.currentItem[0] //cannot intersect with itself
                        && this.placeholder[intersection == 1 ? "next" : "prev"]()[0] != itemElement //no useless actions that have been done before
                        && !$.contains(this.placeholder[0], itemElement) //no action if the item moved is the parent of the item checked
                        && (this.options.type == 'semi-dynamic' ? !$.contains(this.element[0], itemElement) : true)
                        //&& itemElement.parentNode == this.placeholder[0].parentNode // only rearrange items within the same container
                        ) {

                    $(itemElement).mouseenter();

                    this.direction = intersection == 1 ? "down" : "up";

                    if (this.options.tolerance == "pointer" || this._intersectsWithSides(item)) {
                        $(itemElement).mouseleave();
                        this._rearrange(event, item);
                    } else {
                        break;
                    }

                    // Clear emtpy ul's/ol's
                    this._clearEmpty(itemElement);

                    this._trigger("change", event, this._uiHash());
                    break;
                }
            }

            var parentItem = (this.placeholder[0].parentNode.parentNode &&
                    $(this.placeholder[0].parentNode.parentNode).closest('.ui-sortable').length)
                    ? $(this.placeholder[0].parentNode.parentNode)
                    : null,
                    level = this._getLevel(this.placeholder),
                    childLevels = this._getChildLevels(this.helper);

            // To find the previous sibling in the list, keep backtracking until we hit a valid list item.
            var previousItem = this.placeholder[0].previousSibling ? $(this.placeholder[0].previousSibling) : null;
            if (previousItem != null) {
                while (previousItem[0].nodeName.toLowerCase() != 'li' || previousItem[0] == this.currentItem[0] || previousItem[0] == this.helper[0]) {
                    if (previousItem[0].previousSibling) {
                        previousItem = $(previousItem[0].previousSibling);
                    } else {
                        previousItem = null;
                        break;
                    }
                }
            }

            // To find the next sibling in the list, keep stepping forward until we hit a valid list item.
            var nextItem = this.placeholder[0].nextSibling ? $(this.placeholder[0].nextSibling) : null;
            if (nextItem != null) {
                while (nextItem[0].nodeName.toLowerCase() != 'li' || nextItem[0] == this.currentItem[0] || nextItem[0] == this.helper[0]) {
                    if (nextItem[0].nextSibling) {
                        nextItem = $(nextItem[0].nextSibling);
                    } else {
                        nextItem = null;
                        break;
                    }
                }
            }

            var newList = document.createElement(o.listType);

            this.beyondMaxLevels = 0;

            // If the item is moved to the left, send it to its parent's level unless there are siblings below it.
            if (parentItem != null && nextItem == null &&
                    (o.rtl && (this.positionAbs.left + this.helper.outerWidth() > parentItem.offset().left + parentItem.outerWidth()) ||
                            !o.rtl && (this.positionAbs.left < parentItem.offset().left))) {
                parentItem.after(this.placeholder[0]);
                this._clearEmpty(parentItem[0]);
                this._trigger("change", event, this._uiHash());
            }
            // If the item is below a sibling and is moved to the right, make it a child of that sibling.
            else if (previousItem != null &&
                    (o.rtl && (this.positionAbs.left + this.helper.outerWidth() < previousItem.offset().left + previousItem.outerWidth() - o.tabSize) ||
                            !o.rtl && (this.positionAbs.left > previousItem.offset().left + o.tabSize))) {
                this._isAllowed(previousItem, level, level + childLevels + 1);
                if (!previousItem.children(o.listType).length) {
                    previousItem[0].appendChild(newList);
                }
                // If this item is being moved from the top, add it to the top of the list.
                if (previousTopOffset && (previousTopOffset <= previousItem.offset().top)) {
                    previousItem.children(o.listType).prepend(this.placeholder);
                }
                // Otherwise, add it to the bottom of the list.
                else {
                    previousItem.children(o.listType)[0].appendChild(this.placeholder[0]);
                }
                this._trigger("change", event, this._uiHash());
            }
            else {
                this._isAllowed(parentItem, level, level + childLevels);
            }

            //Post events to containers
            this._contactContainers(event);

            //Interconnect with droppables
            if ($.ui.ddmanager)
                $.ui.ddmanager.drag(this, event);

            //Call callbacks
            this._trigger('sort', event, this._uiHash());

            this.lastPositionAbs = this.positionAbs;
            return false;

        },
        _mouseStop: function(event, noPropagation) {

            // If the item is in a position not allowed, send it back
            if (this.beyondMaxLevels) {

                this.placeholder.removeClass(this.options.errorClass);

                if (this.domPosition.prev) {
                    $(this.domPosition.prev).after(this.placeholder);
                } else {
                    $(this.domPosition.parent).prepend(this.placeholder);
                }

                this._trigger("revert", event, this._uiHash());

            }

            // Clean last empty ul/ol
            for (var i = this.items.length - 1; i >= 0; i--) {
                var item = this.items[i].item[0];
                this._clearEmpty(item);
            }

            $.ui.sortable.prototype._mouseStop.apply(this, arguments);

        },
        serialize: function(options) {

            var o = $.extend({}, this.options, options),
                    items = this._getItemsAsjQuery(o && o.connected),
                    str = [];

            $(items).each(function() {
                var res = ($(o.item || this).attr(o.attribute || 'id') || '')
                        .match(o.expression || (/(.+)[-=_](.+)/)),
                        pid = ($(o.item || this).parent(o.listType)
                                .parent(o.items)
                                .attr(o.attribute || 'id') || '')
                        .match(o.expression || (/(.+)[-=_](.+)/));

                if (res) {
                    str.push(((o.key || res[1]) + '[' + (o.key && o.expression ? res[1] : res[2]) + ']')
                            + '='
                            + (pid ? (o.key && o.expression ? pid[1] : pid[2]) : o.rootID));
                }
            });

            if (!str.length && o.key) {
                str.push(o.key + '=');
            }

            return str.join('&');

        },
        toHierarchy: function(options) {

            var o = $.extend({}, this.options, options),
                    sDepth = o.startDepthCount || 0,
                    ret = [];

            $(this.element).children(o.items).each(function() {
                var level = _recursiveItems(this);
                ret.push(level);
            });

            return ret;

            function _recursiveItems(item) {
                var id = ($(item).attr(o.attribute || 'id') || '').match(o.expression || (/(.+)[-=_](.+)/));
                if (id) {
                    var currentItem = {"id": id[2]};
                    if ($(item).children(o.listType).children(o.items).length > 0) {
                        currentItem.children = [];
                        $(item).children(o.listType).children(o.items).each(function() {
                            var level = _recursiveItems(this);
                            currentItem.children.push(level);
                        });
                    }
                    return currentItem;
                }
            }
        },
        toArray: function(options) {
            var o = $.extend({}, this.options, options),
                    sDepth = o.startDepthCount || 0,
                    ret = [],
                    left = 2;

            ret.push({
                "item_id": o.rootID,
                "parent_id": 'none',
                "depth": sDepth,
                "left": '1',
                "right": ($(o.items, this.element).length + 1) * 2
            });

            $(this.element).children(o.items).each(function() {
                left = _recursiveArray(this, sDepth + 1, left);
            });

            ret = ret.sort(function(a, b) {
                return (a.left - b.left);
            });

            return ret;

            function _recursiveArray(item, depth, left) {

                var right = left + 1,
                        id,
                        pid;

                if ($(item).children(o.listType).children(o.items).length > 0) {
                    depth++;
                    $(item).children(o.listType).children(o.items).each(function() {
                        right = _recursiveArray($(this), depth, right);
                    });
                    depth--;
                }

                id = ($(item).attr(o.attribute || 'id')).match(o.expression || (/(.+)[-=_](.+)/));

                if (depth === sDepth + 1) {
                    pid = o.rootID;
                } else {
                    var parentItem = ($(item).parent(o.listType)
                            .parent(o.items)
                            .attr(o.attribute || 'id'))
                            .match(o.expression || (/(.+)[-=_](.+)/));
                    pid = parentItem[2];
                }

                if (id) {
                    ret.push({"item_id": id[2], "parent_id": pid, "depth": depth, "left": left, "right": right});
                }

                left = right + 1;
                return left;
            }

        },
        _clearEmpty: function(item) {

            var emptyList = $(item).children(this.options.listType);
            if (emptyList.length && !emptyList.children().length && !this.options.doNotClear) {
                emptyList.remove();
            }

        },
        _getLevel: function(item) {
            var level = 1;

            if (this.options.listType) {
                var list = item.closest(this.options.listType);
                while (list && list.length > 0 &&
                        !list.is('.ui-sortable')) {
                    level++;
                    list = list.parent().closest(this.options.listType);
                }
            }

//            return level;
        },
        _getChildLevels: function(parent, depth) {
            var self = this,
                    o = this.options,
                    result = 0;
            depth = depth || 0;

            $(parent).children(o.listType).children(o.items).each(function(index, child) {
                result = Math.max(self._getChildLevels(child, depth + 1), result);
            });

            return depth ? result + 1 : result;
        },
        _isAllowed: function(parentItem, level, levels) {
            var o = this.options,
                    isRoot = $(this.domPosition.parent).hasClass('ui-sortable') ? true : false,
                    maxLevels = this.placeholder.closest('.ui-sortable').nestedSortable('option', 'maxLevels'); // this takes into account the maxLevels set to the recipient list

            // Is the root protected?
            // Are we trying to nest under a no-nest?
            // Are we nesting too deep?
            if (!o.isAllowed(this.currentItem, parentItem) ||
                    parentItem && parentItem.hasClass(o.disableNesting) ||
                    o.protectRoot && (parentItem == null && !isRoot || isRoot && level > 1)) {
                this.placeholder.addClass(o.errorClass);
                if (maxLevels < levels && maxLevels != 0) {
                    this.beyondMaxLevels = levels - maxLevels;
                } else {
                    this.beyondMaxLevels = 1;
                }
            } else {
                if (maxLevels < levels && maxLevels != 0) {
                    this.placeholder.addClass(o.errorClass);
                    this.beyondMaxLevels = levels - maxLevels;
                } else {
                    this.placeholder.removeClass(o.errorClass);
                    this.beyondMaxLevels = 0;
                }
            }
        }

    }));

    $.mjs.nestedSortable.prototype.options = $.extend({}, $.ui.sortable.prototype.options, $.mjs.nestedSortable.prototype.options);
})(jQuery);
